Commercial Crew Spacecraft Competition

[erioladastra]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

No matter how it turns out, someone will claim conspiracy, etc., rather than just accept on face value that NASA chose the winners based on who best met the bid criteria.  This delayed announcement is already fueling those theories, because, "clearly", some politician or NASA HQ type with connections is trying to change the results as we speak. 

 - Ed Kyle

I hope and expect that these "political" delays are just various people satisfying themselves that the process has been carried out correctly. We don't want the decision challenged in the courts by someone claiming process has not been followed and that criteria other than those set out are being used to choose the winners.

What delayed announcement?  The Commercial Crew Program has always said July/August.  Bolden fueled speculation that it would be mid July but that was a target date.   Things like the selecting official being on travel for a bit can cause minor "delays".  Other minor things can add time too.  Small wickets to check through for a good roll out. Keep the powder dry, its coming...

[spectre9]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

[Downix]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

The Dream Chaser does it's own final burn, as a quasi third-stage. Boeing's design does not.

[spectre9]

Now it has the prop for a 3rd stage burn too?? 

On hybrid engines?

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

[pathfinder_01]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

In a sense dreamchaser isn't carring around wings. The body is the wing(i.e. lifting body). There will be stuff in thoose areas. And CST 100 is carring around airbags and parachute so wheels vs. no wheels is not a good comparision.

[joek]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

[Prober]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

Was thinking the same.....we don't have the fine details on the CST-100.  Boeing does have alot of experience with composites, so we just don't know.

[manboy]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

Was thinking the same.....we don't have the fine details on the CST-100.  Boeing does have alot of experience with composites, so we just don't know.

What does composites have to do with CST-100?

[anonymous1138]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

In a sense dreamchaser isn't carring around wings. The body is the wing(i.e. lifting body). There will be stuff in thoose areas. And CST 100 is carring around airbags and parachute so wheels vs. no wheels is not a good comparision.

This is a good point. As seen in the previously posted cutaway, there is little space that is not used inside DC structure. It would be interesting to get a feel for how much the wings, rudder, wheels/skid, actuators, etc. weigh in comparison to parachute systems, mortar/pyros. 

[edkyle99]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

It requires an Atlas with a solid booster versus the Atlas 5-402 needed by Dream Chaser.

 - Ed Kyle

[erioladastra]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

Boeing is much farther along on real analysis on their systems on things like power, mass... and they are planning for margin on the early flights and plan to go down smaller if possible.

[Jim]

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

No, Atlas is easier to manrate

[adrianwyard]

Do we know that the CST-100 actually suffered from bloat? With the addition of the SM it is more capable than the Dream Chaser in some respects, having more power on hand for abort, and can use that capability to do station reboost. DC cannot do that.

With the weaker abort capability I suspect that SNC are painted into a corner in terms of staying lightweight: if they gain enough weight to require the addition of a solid motor on the Atlas, their abort capability will look really suspect unless they upgrade that too, which will be very hard to do, and presumably add mass... Plus staying lightweight puts less stress on the TPS. If people are suspicious of the all carbon composite structure on DC (versus traditional manufacturing on CST-100), that same skepticism should be applied to the Liberty capsule too.

So it might be just a design decision. SNC chose the lightweight path. Which decision was best is hard to say right now.

[Robotbeat]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design (that doesn't automatically mean /better/, though it does usually mean less risky schedule-wise).

[anonymous1138]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design ...

Personally, I don't believe that this is an accurate statement.

[Go4TLI]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design ...

Personally, I don't believe that this is an accurate statement.

Me either.  They are completely different designs and as a consequence to that have different concepts of operations which strongly influence the requirements and engineering. 

Neither is more mature and neither is more conservative over the other.  Don't let simple shape of a vehicle try to imply that one can make all the necessary, and correct, deductions. 

[hkultala]

Now it has the prop for a 3rd stage burn too?? 

On hybrid engines?

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

But on DC and draron:

If there is an emergency, the propellant is used for abort.

If there is no emergency, in DC the propellant is used as third stage propellant.

If there is no emergency, on dragon the propellant is used for landing.

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

It's not higher. But it has "worse staging", it's carrying the second stage all the way up to orbit, while DC discards the second stage before orbit.

and DC does not have wings. It just has flatter shape.

[Prober]

Do we know that the CST-100 actually suffered from bloat?

answers to your questions lie in the videos I listed.  No one has picked up on it yet.

 http://forum.nasaspaceflight.com/index.php?topic=22125.960

[pathfinder_01]

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

Small correction. CST100 has a pusher system and will use it's propellant for abort or boost the ISS.  Only Orion has a puller system that is only used for escape.

DC plans to use it for abort, to get into orbit and/or if needed during atmospheric flight.

Dragon just for abort or landing.

[Lars_J]

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

Small correction. CST100 has a pusher system and will use it's propellant for abort or boost the ISS.  Only Orion has a puller system that is only used for escape.

DC plans to use it for abort, to get into orbit and/or if needed during atmospheric flight.

Dragon just for abort or landing.

Incorrect (regarding Dragon). It will only have one set of propellant tanks, so whatever margin is not set aside for landing can be used for orbital maneuvers and/or ISS reboost.